Yes but return may be an issue with expired stamp.

Generally this indicates that your GC is being produced.

Yes if applying for naturalization under the 3 year rule.

No this would not be considered a public benefit for immigration purposes.

You may try this although USCIS may request further evidence.

It means your case is actively in review.

Contact the Indian Consulate General for guidance.

No this was issued in error and should be corrected by CBP.

They may adjust status while in the US as long as this was not their intention upon entry. Consult with an attorney for guidance.

It can take 12-18 months post approval for I485 interview.